cbcvebase.
CVE-2023-28769
published 2023-04-27

CVE-2023-28769: The buffer overflow vulnerability in the library “libclinkc.so” of the web server “zhttpd” in Zyxel DX5401-B0 firmware versions prior to V5.17(ABYO.1)C0 could…

PriorityP182critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
5.42%
91.8th percentile
The buffer overflow vulnerability in the library “libclinkc.so” of the web server “zhttpd” in Zyxel DX5401-B0 firmware versions prior to V5.17(ABYO.1)C0 could allow a remote unauthenticated attacker to execute some OS commands or to cause denial-of-service (DoS) conditions on a vulnerable device.

Affected

2 ranges
VendorProductVersion rangeFixed in
zyxeldx5401-b0_firmware< V5.17(ABYO.1)C0V5.17(ABYO.1)C0
zyxeldx5401-b0_firmware< 5.17\(abyo.1\)c05.17\(abyo.1\)c0

Detection & IOCsextracted from sources · hover to see the quote

path/bin/zhttpd
  • Target the zhttpd web server process for anomalous activity; exploitation requires the zhttp webserver to be network-reachable and requires no authentication
  • Monitor for unexpected OS command execution or child processes spawned from zhttpd, particularly processes running as root following exploitation
  • Alert on outbound binary download attempts (e.g., wget/curl/tftp) initiated by zhttpd or its child processes, as post-exploitation payload staging is a documented attacker technique
  • ·Vulnerability affects more than 40 Zyxel routers and CPE devices, not just the DX5401-B0; scope of affected hardware is broad
  • ·Patched in Zyxel DX5401-B0 firmware V5.17(ABYO.1)C0; devices running prior versions remain vulnerable

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vulncheck9.8CRITICAL
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